1. Field of the Invention
This invention relates to a conduit arrangement for mixing a first gas into a main flow of a second gas, and to a conduit system including such an arrangement. The mixing arrangement has a main conduit for said main flow and a plurality of supply conduits for the first gas which debouch into said main conduit.
2. Description of the Prior Art
Canadian Pat. No. 1106181 describes (FIG. 1) a mixing arrangement of the above-described type in which the number of supply conduits for the gas being admixed is two. These conduits protrude radially through the wall of the cylindrically shaped main conduit and lie in a plane at right angles to the axis of the main conduit. In the main conduit, they are bent through an angle of about 30.degree. in the same sense, and each has a round opening at its extremity, with the mutually parallel center lines of these openings having a separation less than half the internal diameter of the main conduit. Thus the gas being admixed is directed from the openings in mutually parallel but opposite directions with respect to the main conduit axis and circulates in a vortex around the axis in a single direction. This construction makes it possible to achieve complete mixing of the two gases within a short distance downstream from the point of introduction. U.S. Pat. No. 4,390,346, ES-A No. 491321 and EP-A No. 19325 have the same disclosure, as does Japanese patent application No. 60794/80.
U.S. Pat. No. 4,150,817 discloses a different mixing system in which similarly a single vortex is created by two supply conduits which open at the wall of the main conduit. FR-A-No. 2206971 shows a mixing arrangement in which twelve supply conduits open at circumferentially spaced points around the main conduit.